JPH05165429A - Color liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide an inexpensive color liquid crystal display device in which resolution and color mixture can be improved. CONSTITUTION:This device is equipped with a color emitting device 2 arranged on the rear side of a liquid display device 1 and is provided with color emitters of red, green, and blue, a liquid crystal driving circuit 15 to drive the liquid crystal display device, a color emitting device driving circuit 18 to drive the color emitting device, and the liquid crystal driving circuit is equipped with a control signal circuit 151 to drive each dot of the liquid crystal display device replying to red, green, and blue video signals, and the color emitting device driving circuit 18 is equipped with a red/green/blue emitting timing circuit 181 to drive a corresponding color emitter out of the color emitters of the color emitting device, and a color image can be displayed by switching the display of each dot of the liquid crystal display device to display in red, green, or blue.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color display device, and more particularly to a color liquid crystal display device.

[0002]

2. Description of the Related Art A color liquid crystal display device is known in which a color image is displayed by using a color liquid crystal panel such as a liquid crystal color television or a color monitor. Such a conventional color liquid crystal display device has a color liquid crystal panel and is configured by arranging red, green, and blue (R, G, B) pixels in a matrix. In this conventional color liquid crystal display device, R, G, B color filters are formed on one transparent substrate sandwiching liquid crystal, and R, G, B control electrodes are formed on the other transparent substrate. Has been formed. A light source for a backlight is provided on one surface side of the color liquid crystal panel, and the transmitted light that passes through the liquid crystal is controlled based on the control signal supplied to the control electrode. The light passing through each color filter is controlled to display a desired color image.

[0003]

A conventional color liquid crystal display device using such a liquid crystal panel requires a light source for a backlight, and a light beam from this light source is provided on a color filter provided on the liquid crystal panel. Since a color image is displayed by transmitting the light, the color filter absorbs the amount of transmitted light. As a result, sufficient emission brightness cannot be obtained, and the driving power is usually increased in order to increase the light amount of the light source. Along with that, there is a problem that the power consumption of the light source drive system increases.

In order to solve the problems of the conventional color liquid crystal display device, the color display device as disclosed in Japanese Patent Laid-Open No. 61-221785 and Japanese Patent Laid-Open No. 2-1.
A color liquid crystal display device as disclosed in Japanese Patent No. 26228 has been proposed. However, JP-A-61-2178
The color display device of Japanese Patent No. 5 uses electroluminescence (EL element) as a backlight, and uses red,
By arranging the three types of green and blue light emitting materials regularly and eliminating the need for color filters, the conventional problems due to the reduction of the amount of transmitted light due to the use of color filters are solved. In this color display device, the pixel is composed of R, G, and B dots, which is still the same as the conventional one. Therefore, in terms of resolution of the liquid crystal display device and mixing of R, G, and B colors. There was still room for improvement.

In the color liquid crystal display device disclosed in Japanese Patent Laid-Open No. 126228/1990, a phosphor corresponding to a color pixel is formed on one transparent substrate which constitutes a liquid crystal panel, and the other transparent substrate is provided with the color pixel. By forming a control electrode corresponding to the above and displaying a desired color image by illuminating the light source to cause the phosphor to emit light, the color filter is not required. Although the conventional problem due to the decrease in the number of pixels has been solved, this color liquid crystal display device still has the same structure as that of the conventional one, in which pixels are composed of R, G, and B dots. Display resolution, R, G,
There was still room for improvement in terms of B color mixture.

An object of the present invention is to provide a color liquid crystal display device capable of solving the above-mentioned problems of the conventional techniques.

[0007]

A color liquid crystal display device according to the present invention is a liquid crystal display device, and a color light emitting device having red, green, and blue color light emitters arranged on the back surface side of the liquid crystal display device. A liquid crystal driving device for driving the liquid crystal display device; and a color light emitting device driving device for driving the color light emitting device.
The liquid crystal display device is provided with a control signal circuit for driving each dot in response to red, green, and blue video signals, and the color light emitting device driving means is provided for each of the red, green, and blue video signals. In response, a red, green, and blue light emission timing circuit for driving the corresponding color light emitters of the color light emitters of the color light emitting device is provided, and display of each dot of the liquid crystal display device is performed. It is characterized in that a color image can be displayed by switching to red, green or blue display.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the basic structure of a color liquid crystal display device of the present invention. The color liquid crystal display device of this embodiment includes a liquid crystal display device 1 for monochrome display and red, green and blue (R, G, B) arranged behind the liquid crystal display device 1.
And a fluorescent display tube 2 having a light-emitting body. A video signal processing circuit 16 converts a video signal received by a tuner 17 in a television receiver or the like into a liquid crystal drive circuit 15.
By applying voltages corresponding to the R, G, and B video signals to the liquid crystal display device 1 and the fluorescent display tube 2 via the fluorescent display tube driving circuit 18 and the fluorescent display tube 2, color image display is performed. It is a thing.

According to the present invention, the liquid crystal drive circuit 15 includes a control signal circuit 151, and the fluorescent display tube drive circuit 1 is provided.
8 includes a red-green-blue light emission timing circuit 181.
The control signal circuit 151 drives each dot of the liquid crystal display device 1 in response to the red, green, and blue video signals from the video signal processing circuit 16, while the red, green, and blue light emission timing circuit 18 is driven.
1 is synchronized with this, in response to each of the red, green, and blue video signals from the video signal processing circuit 16, the red, green, and blue (R, G, B) light emitters of the fluorescent display tube 2 are provided. It operates to drive the corresponding color emitters.

As described above, in the color liquid crystal display device of the present invention, the fluorescent display tube 2 is switched to R, G and B colors to emit light, and the liquid crystal panel 1 is also operated in correspondence with R, G and B signals. As a result, when the fluorescent display tube 2 emits R color, the liquid crystal panel signal also becomes an R color signal. The same applies for G and B emission. Therefore, R, G, and B colors are obtained in one dot portion of the liquid crystal display, and full color image display is possible. In this embodiment, full-color image display is performed by a television signal, but the present invention is not limited to this.

FIG. 2 is a schematic sectional view showing a specific structural example of a color liquid crystal display device as an embodiment of the present invention.
As shown in FIG. 2, in the liquid crystal panel 1, a deflector 7 is arranged on the surface of the liquid crystal windshield 4, and
The Y electrode 5 is arranged on the back surface of the liquid crystal rear glass, the X electrode 3 is arranged on the inner surface of the liquid crystal rear glass 8, and the deflection plate 9 is arranged on the rear surface of the liquid crystal rear glass 8. It's a sandwich of six. The liquid crystal display panel 1 has a simple matrix driving method and an active matrix driving method, but the present invention is not influenced by the driving method.

On the other hand, the fluorescent display tube 2 arranged behind the liquid crystal panel 1 includes a windshield 10 and a cathode 1.
1, a grid 12, and a substrate 14 in which anodes 13R, 13G, and 13B made of R, G, and B phosphors are arranged in stripes or dots. Windshield 1 of fluorescent display tube 2 used as a backlight
0 is ground glass so that light is scattered. In addition, the R, G, B light emitting layers 13R, 13G, 13B
Are connected by lead lines R, G, B respectively, and R,
The electrodes are divided into G and B colors and the electrodes are drawn out.

FIG. 3 is a timing chart of signals applied to the fluorescent display tube 2 and the liquid crystal display device 1. As shown in FIG. 3, when the fluorescent display tube 2 emits R light (A _R ), an R video signal ( _{BR 1} , BR ₂ ...) Is applied to the liquid crystal panel 1, and then the fluorescent display tube 2 is turned on. A _G video signal (B _G1 , B _G2 , ...) Is applied to the liquid crystal panel 1 during G light emission (A _G ), and then, when the B light emission (A _B ) of the fluorescent display tube 2 occurs. By applying the B video signal ( _BB1 , _BB2 , ...) To, the R, G, and B emission colors are displayed in one dot portion of the liquid crystal panel 1, and full color display is possible.

As described above, in the color liquid crystal display device according to the present invention, the fluorescent display tube having the R, G, B luminous bodies 13R, 13G, 13B is used as the backlight.
The emission of the fluorescent display tube used as a backlight is switched to R, G, B by the timing signals A _R , A _G , A _B ,
Color display can be performed by applying R, G, and B control signals B _R , B _G , and B _B to the liquid crystal panel 1 in accordance with the timing to change the amount of light.

Although the fluorescent display tube is used as the color light emitting device in the above-mentioned embodiments, the present invention is not limited to this, and for example, electroluminescence (EL element), PDP (plasma) as the color light emitting device. Similar effects can be obtained by using a display) and an LED.

[0017]

According to the structure of the color liquid crystal display device of the present invention as described above, since the color filter is not required, the cost can be reduced accordingly. Also,
Since the color filter is unnecessary, the light transmittance can be improved.

Further, according to the configuration of the present invention, pixels are formed by R, G, and B3 dots in the related art.
Since the dot becomes one pixel (R, G, B), the dot resolution can be improved, and moreover, the color mixture can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a color liquid crystal display device of the present invention.

FIG. 2 is a schematic cross-sectional view showing a specific structural example of a color liquid crystal display device as one embodiment of the present invention.

FIG. 3 is a timing diagram of signals applied to a fluorescent display tube and a liquid crystal display device.

[Explanation of symbols]

 1 Liquid crystal display device 2 Fluorescent display tube 3 X electrode 4 Liquid crystal windshield 5 Y electrode 6 Liquid crystal 7 Deflection plate 8 Liquid crystal rear glass 9 Deflection plate 10 Fluorescent display tube front glass 11 Cathode 12 Grid 13R Phosphor R anode 13G Phosphor G anode 13B Phosphor B anode 14 Substrate 15 Liquid crystal drive circuit 16 Video signal processing circuit 17 Tuner 18 Fluorescent display tube drive circuit 151 Control signal circuit 181 Red green blue light emission timing circuit

Claims (3)

[Claims] 1. A liquid crystal display device, a color light emitting device having red, green, and blue color light emitters arranged on the back surface side of the liquid crystal display device, and liquid crystal driving means for driving the liquid crystal display device. A color light emitting device driving means for driving the color light emitting device, wherein the liquid crystal driving means drives each dot of the liquid crystal display device in response to red, green and blue video signals. And a control signal circuit, wherein the color light emitting device driving means responds to each of the red, green, and blue video signals to cause the corresponding color light emitting device of the color light emitting device to emit light of a corresponding color. It has a red, green, and blue emission timing circuit to drive it.
A color liquid crystal display device, wherein a color image can be displayed by switching display of each dot of the liquid crystal display device to red, green or blue display. 2. The color liquid crystal display device according to claim 1, wherein the color light emitting device is a fluorescent display tube. 3. The color liquid crystal display device according to claim 1, wherein the liquid crystal display device is a monochrome display.